1. Field of the Invention
The present invention relates to weapons that include an elongated barrel having a rifled bore. More particularly, the present invention relates to an improved apparatus for removing oscillation in weapons barrels during the firing of a projectile by placement of a plurality of loosely spaced rings at the muzzles end of the barrel on a ring carrier wherein a retainer that holds the rings in position on the external surface of the muzzle end of the barrel, the ring holder defining a reduced diameter portion of the barrel at the muzzle end.
2. General Background
Rifled barrels oscillate when fired at a rate determined by the rigidity of the barrel. This movement resembles a coil spring in its motion, increasing in pitch as the bullet or projectile moves down the barrel. The pitch of the oscillation is at its greatest at the breech end because the barrel is most rigid at that point of the barrel/action joint.
Most barrels are made with a taper from the breech end to the muzzle end. The smallest diameter is provided at the muzzle end on most weapons. This variation in diameter creates a faster pitch in the oscillation at the muzzle and makes for a variable in bullet placement upon the exit of the barrel.
Several patents have issued that relate generally to the problem of stabilizing a rifle barrel. An example of an early stabilizer for a firearm can be seen in U.S. Pat. No. 2,752,714 issued to L. F. Landwehr. The Landwehr patent disclosed an invention that pertains to stabilizers such as are used on rifles in the practice known as bench shooting in which the rifle is supported on fixed support and fires repeatedly from such fixed position. The Landwehr '714 patent discloses a base having plurality of hydraulic cylinders as part of the system for stabilizing the firearm barrel.
Some gun barrels use a composite construction that includes circumferentially layered portions at the muzzle end of the barrel. For example, the Hogg U.S. Pat. No. 2,249,899 discloses a gun barrel construction that the inventor alleges is adapted to minimize barrel whip. The gun barrel construction of the '899 patent includes an outer sleeve of any elastic plastic material of high vibration damping properties co-adhesively bonded to the barrel, the inner elastic sleeve being covered with a protective sleeve co-adhesiably bonded thereto. Other early patents that include composite firearm barrels and/or the layering of materials on a steel or metal barrel include the U.S. Pat. Nos. 2,845,741 to Day; 2,941,326 to Hamil; 3,299,558 to Karl; 3,439,441 to Lawley; and 3,742,640 to Thomsen.
The Robert Joseph U.S. Pat. No. 4,057,924 provides a device for adjusting the force between the rifle barrel and the forearm of the stock comprising a stabilizing block having a concave groove formed on the upper surface thereof to engage the rifle barrel. An adjuster screw having an enlarged head is rotatably positioned in a socket formed in the lower side of the stabilizing block. Retaining pins retain the head of the screw within the socket. A screw housing is rigidly secured within the stock close to the end of the forearm. The adjuster screw is threadedly secured to the screw housing such that the stabilizing block may be moved relative to the screw housing and forearm to adjust the force on the rifle barrel.
The Debona et al. U.S. Pat. No. 4,296,669 discloses a rocket tube launcher with a cast-in place tube support bulkhead. The Ashton et al. U.S. Pat. No. 4,469,537 discloses an aluminum-magnesium-manganese alloy cold rolled to produce armor plate with allegedly improved ballistic properties.
A forearm for firearms is disclosed in U.S. Pat. No. 2,312,150. A chamber structure for guns is disclosed in U.S. Pat. No. 2,952,089. The mounting of a gun barrel in its stock is disclosed in U.S. Pat. No. 2,967,368. A rifle barrel that includes layers is disclosed in the Grandy et al. U.S. Pat. No. 3,228,298. The Recker U.S. Pat. No. 3,340,641 provides a method for improving the accuracy of firearms by reducing barrel vibration.
The Bettermann et al. U.S. Pat. No. 3,732,778 discloses a device on gun barrels for the reduction of the angle jump of a projectile, which comprises at least one reinforcement member fitted to the forward range of a gun barrel and is adapted to dampen bending oscillations occurring upon firing of the gun barrel. The Bettermann et al. patent '778 patent discloses a plurality of reinforcement members fitted to the forward range of a gun barrel and adapted to dampen bending oscillations upon firing of the gun barrel, the reinforcement members being disposed in the vicinity of muzzle of the gun barrel and comprising bodies enlarging in the range of plane-moment of an archer of the gun barrel. The reinforcement members are disposed in spaced apart locations at predetermined distances within the range of adjacent occurring loading peaks in the vicinity of the muzzle of the gun barrel.
A method and apparatus for explosive autofrettage is disclosed is U.S. Pat. No. 3,751,954. The '954 patent discloses an apparatus for producing residual compressive hoop stress at the inner bore of thick-walled tubes by the use of explosive charges positioned along the axis of said tubes. The explosive charge may be placed by itself along the axis of the thick-walled tube or may be enclosed in a second inner tube placed inside the thick-walled tube with an energy transmitting medium filling the space between the two tubes. The explosive charge is detonated producing pressure which plastically expands the thick-walled tube and causes residual compressive hoop stress to be developed at the inner bore upon dissipation of the pressure and elastic contraction of the thick-walled tube.
More recent patents that discuss the problem of accuracy include the Elspass U.S. Pat. No. 4,649,797 providing a gun barrel with reduced repeative jump angle. The '797 patent discloses an improved gun barrel in a tank cannon assembly having a recoiling mass. This gun barrel has an alleged increased target impact precision by virtue of stabilizing the bending oscillations and/or vibrations during firing, thereby making the jump angle more uniform from one firing to the next one. The L/D ratio of the gun barrel is stated as larger than 52 (where L represents the length of the gun barrel and D represents the caliber diameter). The gun barrel jacket has a frustro-conically shaped portion extending from the muzzle towards the rear of the gun barrel which is adjoined by a cylindrically shaped portion. The gun barrel is supported on a cradle along the latter portion. The gun barrel exhibits a continuous unbuckled bending line in its static and dynamic conditions between its muzzle and the cylindrical jacket portion. The frustro-conically shaped and cylindrically shaped portions merge into each other and have identical diameters along their merging line. The cylindrically shaped jacket portion is supported with respect to the firing direction along a distance a which is &lt;7 D. The center of gravity of the recoiling mass is disposed within the frustro-conically shaped jacket portion of the gun barrel.
The Krumm U.S. Pat. No. 5,077,926 patent discloses a gun barrel said to be equipped with optimizing rifling. In order to improve the service life of prior art gun tubes and to improve the ballistics of a projectile fired through them, the '926 patent provides a gun tube with an "optimized" variable rifling which products a rifling force curve (R(x)) along the gun tube (x) which has an essentially trapezoidal shape with alleged reduced rifling force maximum compared to the rifling force curves of conventional constant rifling.
The Oskarsson et al. U.S. Pat. No. 5,191,165 relates to a method of producing rifled, non-metallic barrels of composite material in the form of a fiber-reinforced thermosetting matrix for rocket and grenade launcher ordnance, and barrels produced in accordance therewith.
The Jackson et al. U.S. Pat. No. 4,669,212 provides a gun capable of operating at relatively higher temperatures. The barrel of the gun is made up of at least two layers. The inner layer is of a refractory material which may be a metal refractory or a non-metal refractory. The liner is bonded to an outer jacket material formed of an alloy of nickel, aluminum and molybdenum. The coefficient of expansion of the liner and of the jacket are relatively low so that the gun does not expand extensively when heated by intensive use. The jacket metal is of higher strength at elevated temperature than is the conventional gun barrel steel.
The Petrovich U.S. Pat. No. 5,212,328 discloses a non-metallic gun barrel having a longitudinally rigid tube exterior capable of radial elastic deformation upon passage of a projectile therethrough. Liner segments fixed at the inner diameter of the barrel exterior are abutted end to end and form spiraled rifling structures comprised of shallow channels and ridges between the channels. Radial gaps between sides of the liners can be partly filled by radial projections of elastomeric material of the barrel exterior. The radial projections expand inwardly to seal against a projectile bearing against the inner periphery of the barrel as the projectile is fired from the barrel.
A United States Statutory Invention Registration H342 discloses an, apparatus to improve the accuracy of weapons through barrel flexure.
The Pedgonay U.S. Pat. No. 4,130,959 provides a rifled ordinance mounting system for controlling trajectory errors normally imparted on projectile emergence as result of barrel torsional windup and spring back includes a mounting which holds the barrel at the muzzle, the holding being with a torsional rigidity exceeding the torsional rigidity of the barrel.
An anti-twist forearm mounting system is disclosed in U.S. Pat. No. 4,406,080. The forearm of a pump shotgun is mounted for a reciprocal movement with respect to the magazine tube through a coupling system which prevents twisting of the forearm. A coupling system includes grooves in the exterior sidewall of the magazine tube and detents on the exterior sidewall of the forearm mount tube in registration with the grooves.
U.S. Pat. No. 4,537,742 discloses a method for forming articles from difficult to fabricate materials with precise internal dimensions. The article is first formed to approximate dimensions as a body using the material in powdered form. Plasma spray forming is proposed. The powdered formed body is then brought to its final dimensions by consolidating and densifying the body about the densifying mandrel having a coefficient of expansion which is higher and outer dimensions which are slightly smaller than that of the body.
A countercoil and recoil damper for an automatic firearm which ensures floating support of the weapon during automatic bursts of fire is disclosed in U.S. Pat. No. 4,667,566. A barrel vibration dampening device for rifles is disclosed in U.S. Pat. No. 4,864,761. The vibration dampening device disclosed in the '761 patent is provided in the forearm of a rifle for engaging a cantilevered barrel forward of the rifle action for dampening the vibration of the barrel as a bullet moves through the barrel to the muzzle. The vibration dampening device includes an insert that is mounted in a cavity formed in the forearm. The insert includes a threaded bore with a pressure screw threadably mounted in the bore in which the threaded screw has a pointed end engaging the barrel at a selected point. A tool access aperture extends through the forearm from the lower profile surface in alignment with the threaded bore for enabling a tool to be inserted through a tool access aperture to engage the pressure screw to rotate the pressure screw to the desired position. A locking means is provided for locking the pressure screw in place when the correct pressure is obtained.
The Petrovich U.S. Pat. No. 5,183,958 non-metallic gun barrel. Another non-metallic gun barrel is disclosed in the Petrovich U.S. Pat. No. 5,196,637. Another Krumm U.S. Pat. No. 5,337,504 relates to a gun tube having a spin curve with a variable spin angle. Some of these patents relate generally to the problem of barrel vibration during firing. However, none of this known prior art is believed a solution to the problem of inherent oscillation in rifle metal washers or rings placed in loose fit arrangement on the outside of the muzzle end of the barrel.